1. Field of the Invention
The present general inventive concept relates to a scanning apparatus to read image information from a document sheet and a method of preventing damage of gears of the scanning apparatus.
2. Description of the Related Art
In general, a scanning apparatus is an apparatus for reading literal information and/or image information from a document sheet on which the literal information and/or the image information is recorded, and is applicable to a transmitting portion of a facsimile or a combined apparatus for printing, a scanning portion of a scanner and a copier, etc.
The scanning apparatus includes a driving roller for transferring the document sheet at a predetermined speed, and a reading unit for reading the image information from the document sheet. Usually, the driving roller is in contact with a scan glass of the reading unit at a predetermined contacting pressure. A driving gear is joined to the driving roller, and a driving motor is connected to the driving gear via a series of gears.
When a sheet jam occurs during transferring the document sheet, the document sheet must be removed from a sheet transfer path. To this end, it is preferable that the driving roller is spaced from the scan glass of the reading unit, and the driving gear is separated from the series of gears. After the jammed sheet is removed, the driving roller is controlled to be in contact with the scan glass, and the driving gear is again connected to the series of gears. When the driving gear is again connected to the series of gears, the driving gear and/or the series of gears may be damaged as the teeth of the driving gear and the series of gears collide with each other.
Since the reading unit reads information at a resolution of several hundred and higher DPI (dot per inch), the document sheet must be very precisely transferred. As described above, when the driving gear or the series of gears are damaged, the precise transference of the document sheet deteriorates.